scholarly journals Novel Object Detection and Multiplexed Motion Representation in Retinal Bipolar Cells

2021 ◽  
Author(s):  
Alon Poleg-Polsky ◽  
John A Gaynes ◽  
Samuel A Budoff ◽  
Joshua B Hunt ◽  
Michael J Grybko
Keyword(s):  
Object Detection ◽  
Glutamate Release ◽  
Bipolar Cells ◽  
Motion Processing ◽  
Human Visual Perception ◽  
Continuous Motion ◽  
Novel Object ◽  
Rf Components ◽  
Novel Objects ◽  
Retinal Bipolar Cells

Antagonistic interactions between the center and surround receptive field (RF) components lie at the heart of the computations performed in the visual system. Center-surround RFs are thought to enhance responses to spatial contrasts (i.e., edges), but how they contribute to motion processing is unknown. Here, we addressed this question in retinal bipolar cells, the first visual neuron with classic center-surround interactions. We found that bipolar glutamate release emphasizes objects that emerge in the RF; their responses to continuous motion are smaller, slower, and cannot be predicted by signals elicited by stationary stimuli. The alteration in signal dynamics induced by novel objects dwarfs the enhancement of spatial edges and can be explained by priming of RF surround during continuous motion. These findings echo the salience of human visual perception and demonstrate an unappreciated capacity of the center-surround architecture to facilitate novel object detection and multiplexed encoding of distinct sensory modalities.

scholarly journals Calcium spike-mediated digital signaling increases glutamate output at the visual threshold of retinal bipolar cells

2015 ◽  
Vol 113 (2) ◽  
pp. 550-566 ◽  
Author(s):  
Mikhail Y. Lipin ◽  
Jozsef Vigh
Keyword(s):  
Light Intensity ◽  
Ganglion Cells ◽  
Glutamate Release ◽  
Bipolar Cells ◽  
Calcium Spikes ◽  
Temporal Precision ◽  
Axon Terminals ◽  
Visual Threshold ◽  
Graded Responses ◽  
Retinal Bipolar Cells

Most retinal bipolar cells (BCs) transmit visual input from photoreceptors to ganglion cells using graded potentials, but some also generate calcium or sodium spikes. Sodium spikes are thought to increase temporal precision of light-evoked BC signaling; however, the role of calcium spikes in BCs is not fully understood. Here we studied how calcium spikes and graded responses mediate neurotransmitter release from Mb-type BCs, known to produce both. In dark-adapted goldfish retinal slices, light induced spikes in 40% of the axon terminals of intact Mbs; in the rest, light generated graded responses. These light-evoked membrane potentials were used to depolarize axotomized Mb terminals where depolarization-evoked calcium current ( ICa) and consequent exocytosis-associated membrane capacitance increases (Δ Cm) could be precisely measured. When evoked by identical dim light intensities, spiking responses transferred more calcium (QCa) and triggered larger exocytosis with higher efficiency (Δ Cm/QCa) than graded potentials. QCa was translated into exocytosis linearly when transferred with spikes and supralinearly when transferred with graded responses. At the Mb output (Δ Cm), spiking responses coded light intensity with numbers and amplitude whereas graded responses coded with amplitude, duration, and steepness. Importantly, spiking responses saturated exocytosis within scotopic range but graded potentials did not. We propose that calcium spikes in Mbs increase signal input-output ratio by boosting Mb glutamate release at threshold intensities. Therefore, spiking Mb responses are suitable to transfer low-light-intensity signals to ganglion cells with higher gain, whereas graded potentials signal for light over a wider range of intensities at the Mb output.

Subcellular Localization and Complements of GABAA and GABAC Receptors on Bullfrog Retinal Bipolar Cells

2000 ◽  
Vol 84 (2) ◽  
pp. 666-676 ◽  
Author(s):  
Jiu-Lin Du ◽  
Xiong-Li Yang
Keyword(s):  
Subcellular Localization ◽  
Receptor Antagonist ◽  
Gaba Receptor ◽  
Drug Application ◽  
Bipolar Cells ◽  
Visual Signals ◽  
Receptor Subtypes ◽  
Inner Retina ◽  
Axon Terminals ◽  
Retinal Bipolar Cells

γ-Aminobutyric acid (GABA) receptors on retinal bipolar cells (BCs) are highly relevant to spatial and temporal integration of visual signals in the outer and inner retina. In the present work, subcellular localization and complements of GABAA and GABACreceptors on BCs were investigated by whole cell recordings and local drug application via multi-barreled puff pipettes in the bullfrog retinal slice preparation. Four types of the BCs (types 1–4) were identified morphologically by injection of Lucifer yellow. According to the ramification levels of the axon terminals and the responses of these cells to glutamate (or kainate) applied at their dendrites, types 1 and 2 of BCs were supposed to be off type, whereas types 3 and 4 of BCs might be on type. Bicuculline (BIC), a GABAA receptor antagonist, and imidazole-4-acetic acid (I4AA), a GABAC receptor antagonist, were used to distinguish GABA receptor-mediated responses. In all BCs tested, not only the axon terminals but also the dendrites showed high GABA sensitivity mediated by both GABAA and GABACreceptors. Subcellular localization and complements of GABAA and GABAC receptors at the dendrites and axon terminals were highly related to the dichotomy of offand on BCs. In the case of off BCs, GABAA receptors were rather evenly distributed at the dendrites and axon terminals, but GABAC receptors were predominantly expressed at the axon terminals. Moreover, the relative contribution of GABAC receptors to the axon terminals was prevalent over that of GABAA receptors, while the situation was reversed at the dendrites. In the case of on BCs, GABAA and GABAC receptors both preferred to be expressed at the axon terminals; relative contributions of these two GABA receptor subtypes to both the sites were comparable, while GABAC receptors were much less expressed than GABAA receptors. GABAA, but not GABAC receptors, were expressed clusteringly at axons of a population of BCs. In a minority of BCs, I4AA suppressed the GABAC responses at the dendrites, but not at the axon terminal, implying that the GABAC receptors at these two sites may be heterogeneous. Taken together, these results suggest that GABAA and GABAC receptors may play different roles in the outer and inner retina and the differential complements of the two receptors on off and on BCs may be closely related to physiological functions of these cells.

204 Ca2+ buffering in axon terminals of goldfish retinal bipolar cells

1993 ◽  
Vol 18 ◽  
pp. S28
Author(s):  
Katsunori Kobayashi ◽  
Masao Tachibana ◽  
Takashi Okada
Keyword(s):  
Bipolar Cells ◽  
Axon Terminals ◽  
Retinal Bipolar Cells

scholarly journals Disfluencies signal reference to novel objects for adults but not children

2017 ◽  
Vol 45 (3) ◽  
pp. 581-609 ◽  
Author(s):  
Sarah J. OWENS ◽  
Justine M. THACKER ◽  
Susan A. GRAHAM
Keyword(s):  
Young Children ◽  
Spoken Language ◽  
The Novel ◽  
Novel Object ◽  
Filled Pauses ◽  
Novel Objects ◽  
Novel Targets ◽  
The Way ◽  
Familiar Objects

AbstractSpeech disfluencies can guide the ways in which listeners interpret spoken language. Here, we examined whether three-year-olds, five-year-olds, and adults use filled pauses to anticipate that a speaker is likely to refer to a novel object. Across three experiments, participants were presented with pairs of novel and familiar objects and heard a speaker refer to one of the objects using a fluent (“Look at the ball/lep!”) or disfluent (“Look at thee uh ball/lep!”) expression. The salience of the speaker's unfamiliarity with the novel referents, and the way in which the speaker referred to the novel referents (i.e., a noun vs. a description) varied across experiments. Three- and five-year-olds successfully identified familiar and novel targets, but only adults’ looking patterns reflected increased looks to novel objects in the presence of a disfluency. Together, these findings demonstrate that adults, but not young children, use filled pauses to anticipate reference to novel objects.

scholarly journals Potentiating Action of Propofol at GABAAReceptors of Retinal Bipolar Cells

2011 ◽  
Vol 52 (5) ◽  
pp. 2497 ◽  
Author(s):  
Lan Yue ◽  
An Xie ◽  
Karol S. Bruzik ◽  
Bente Frølund ◽  
Haohua Qian ◽  
...  
Keyword(s):  
Bipolar Cells ◽  
Retinal Bipolar Cells

scholarly journals A novel object detection technique for dynamic scene and static object

2016 ◽  
Vol 54 ◽  
pp. 08003
Author(s):  
Xiu Li ◽  
Liansheng Chen ◽  
Zhixiong Yang ◽  
Huimin Wang
Keyword(s):  
Object Detection ◽  
Detection Technique ◽  
Dynamic Scene ◽  
Novel Object ◽  
Static Object

Spontaneous Oscillatory Activity of Starburst Amacrine Cells in the Mouse Retina

2005 ◽  
Vol 94 (3) ◽  
pp. 1770-1780 ◽  
Author(s):  
Jerome Petit-Jacques ◽  
Béla Völgyi ◽  
Bernardo Rudy ◽  
Stewart Bloomfield
Keyword(s):  
Feedback Inhibition ◽  
Glutamate Release ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Kainate Receptors ◽  
Oscillatory Activity ◽  
Mouse Retina ◽  
Inner Plexiform Layer ◽  
Experimental Conditions ◽  
Starburst Amacrine Cells

Using patch-clamp techniques, we investigated the characteristics of the spontaneous oscillatory activity displayed by starburst amacrine cells in the mouse retina. At a holding potential of –70 mV, oscillations appeared as spontaneous, rhythmic inward currents with a frequency of ∼3.5 Hz and an average maximal amplitude of ∼120 pA. Application of TEA, a potassium channel blocker, increased the amplitude of oscillatory currents by >70% but reduced their frequency by ∼17%. The TEA effects did not appear to result from direct actions on starburst cells, but rather a modulation of their synaptic inputs. Oscillatory currents were inhibited by 6-cyano-7-nitroquinoxalene-2,3-dione (CNQX), an antagonist of AMPA/kainate receptors, indicating that they were dependent on a periodic glutamatergic input likely from presynaptic bipolar cells. The oscillations were also inhibited by the calcium channel blockers cadmium and nifedipine, suggesting that the glutamate release was calcium dependent. Application of AP4, an agonist of mGluR6 receptors on on-center bipolar cells, blocked the oscillatory currents in starburst cells. However, application of TEA overcame the AP4 blockade, suggesting that the periodic glutamate release from bipolar cells is intrinsic to the inner plexiform layer in that, under experimental conditions, it can occur independent of photoreceptor input. The GABA receptor antagonists picrotoxin and bicuculline enhanced the amplitude of oscillations in starburst cells prestimulated with TEA. Our results suggest that this enhancement was due to a reduction of a GABAergic feedback inhibition from amacrine cells to bipolar cells and the resultant increased glutamate release. Finally, we found that some ganglion cells and other types of amacrine cell also displayed rhythmic activity, suggesting that oscillatory behavior is expressed by a number of inner retinal neurons.

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